The invention relates to a shoe, essentially comprised of a sole subassembly and an upper structure subassembly, which sole and upper structure are releasably joined together.
Typically shoes of different colors, appearance, and structure are purchased and worn based on their compatibility with specific items of clothing which the shoe wearer desires to wear. Thus, an assortment of shoes will be acquired by a wearer, not only for leisure and sports applications but also in shoes for everyday wear. It is well known that shoe soles are more costly to manufacture than shoe uppers, for reasons of the materials required and also the manufacturing steps involving machine operations and/or manual operations.
In order to satisfy the desire to wear a variety of shoes of different colors and forms to match frequent changes of clothing, heretofore it has been necessary for a wearer to accumulate a numerically large stock of different shoes. The costs of this stratagem are prohibitive for broad sectors of the population.
A shoe of the general type described initially supra is known (U.S. Pat. No. 4,103,440), in which the sole has a generally trough-shaped (flattened U-shaped) cross section, and the upper structure penetrates into the sole structure to the level of the upper ("inner") surface of the sole proper, or farther. In this known shoe, the said penetratingly extended part of the upper structure tends to transmit movement which is uncomfortable to the wearer. The flexing of the sole when the wearer walks or runs causes buckling and bulging of the material of the upper structure in the natural flexural zones of the shoe. Loci of rubbing develop at the lateral regions of the wearer's foot which are hazardous to a wearer seeking a long duration of wear.